“If you have one clock … you are peaceful and have no worries,” says Van Baak, fingering a length of cable connecting two of his machines. “If you have two clocks … you start asking, ‘What time is it, really?'”

Van Baak is in a better position to answer that question than most. He’s part of a community of about 400 geek hobbyists taking advantage of a glut of surplus precision timekeeping gear to pursue a serious interest in very precise timekeeping. They call themselves Time Nuts, and they spend their spare cycles collecting, repairing, tweaking — and occasionally using — super-precise clocks.

With the end of the Cold War, and with telecommunications technology advancing rapidly, surplus stores and eBay have filled up with discarded precision time equipment once beyond the reach of all but governments. Cesium clocks, rubidium clocks and even the occasional hydrogen maser can be had for less than a decent laptop. A recent search on eBay turned up an HP 5061B cesium standard for sale for $2,000, and you can get a telecom surplus rubidium standard for less than $400. Some of this equipment costs upwards of $50,000 new.